Apparatus for heat treating materials



Oct. 31, 1933. R. w. HYDE 1,932,409

APPARATUS FOR HEAT TREATING IATERIALS' Filed March 25, 1931 4 Sheets-Sheet 1 FIG. I

' INVEN;0& BY 2 A TTORNEY S.

Oct. 31, 1933. R. w. HYDE APPARATUS FOR HEAT TREATING MATERIALS Filed March 25. 1931 4 Sheets-Sheet 2 A TTORNEYS.

O 1933- R. w. HYDE 1,932,409

APPARATUS FOR HEAT TREATING MATERIALS Filed March 25, 1931 4 Sheets-Sheet 3 (\l I 1 LO r f T P l j INV TOR.

BY MY A TTORN S.

Oct. 31, 1933. R. w. HYDE 1,932,409

APPARATUS FOR HEAT TREATING MATERIALS Filed March 25, 1931 4 Sheets-Sheet 4 FIG. 4

BY M +Q I A T TORNEYS.

Patented Oct. 31, 1933 APPARATUS FOR HEAT TREATING --,MATERIALS Reed W. Hyde, Summit, N. J. Application March 25, 1931.v Serial No.4525,161

, 7 Claims.

This invention relates to an apparatus for heat treating material and more particularly to an apparatus for successively treating said material in layers to produce a light weight cellular product.

The invention provides for completely heat treating each layer beforethe next successive layer is applied thereto to form a cellular cake which is substantially homogeneous and in which the various layers are joined together as an integral unit. The heat treatment may be accomplished by applying hot gases to the various layers, or by drawing the gases through said layers as they are successively applied in a heat treating apparatus.

The invention may be applied particularly to the burning of materials, such as clay, to form a concrete aggregate material. It may also be applied to other materials which have a relative- 1y extended softening range, rather than a sharp melting point, such as, shales, argillites and similar rocks.

The invention also consists in certain new and original features of construction and combinationsof parts hereinafter set forth and claimed.

Although the novel features which are believed to be characteristic of this invention will be particularly'pointed out in the claims appended hereto, the invention itself, as to its objects and advantages, and the manner in which it may be carried out, may be better understood by referring to the following description taken in connection with the accompanying drawings forming a part thereof, in which 3 Fig. 1 is a sideelevation of an apparatus constructed in accordance with the present invention;

Fig. 2 is a section taken on the line 2-2 of Fig. 1;

Fig. 3 is a side elevation of a modified form of apparatus; and r Fig. 4 is a section taken on the line 4-4 of Fig. 3.

Like reference characters denote like parts in.

tural steel or other suitable supporting material ty of pallets 12, having perforate bottoms or grates 13, are supported. Said pallets are propelledalong track 11 by suitable means, such as driving wheel 14, which is actuated from a motor 15 through intermediate gears 16. A wind box 20 is supported on framework 10 beneath pallets 12 in such position that the pallets"12 pass'over said wind box as they are progressively moved along track 11. The top of said Wind box is adapted to make a close seal with the-bottoms of said pallets whereby leakage of gases is reduced to a minimum. Said wind box may beconnected by a pipe 22 to a suitable source of suction (not shown) and may be provided with hinged doors '21 which afford access tothe interior for cleaning purposes.

A heating chamber 25 is also supported by said frame lO and is positioned above said pallets and in communication therewith. Said chamber comprises roof 26, side walls 2'7 and bottom members 28, the latter projecting slightly over the side walls of the pallets to protect them from the intense heat within the chamber and to effect a relatively close joint whereby leakage of gases is prevented. Flexible members 29 of heat resist- .ing material may be secured to the members 28 8 and engage the sides'of pallets 12 for effecting a further seal. A plurality of ports 30 are formed in the side walls 27 and communicate with fuel burners 31 by which highly heated gases are admitted to the heating chamber. These ports are so located that the gases'entering therethrough make contact with and" cover substantially the entire surface of the material being transported throughthe heating chamber by the pallets. It is obvious that the ports may be variously located, as for example, inthe side-wallsprooL-bottom members or the end walls of the chamber, depending upon the particularfuel employed and the size of the chamber. Furthermore, they are so arranged asto number and position that the heat in the various parts of the chamber may be controlled and preferably so that uniform heat may be maintained in the entire chamber.

1 In the form ofthe invention illustrated, the side walls are spaced back from the edges of the pallets to provide a combustion chamber extending the length of the heating chamber on either side thereof. In this combustion chamber the fuel-air mixture which is received through ports 30 may be completely burned before the hot gases contact with the material undergoing treatment. This is particularly advantageous where a type of burner is employed which normally throws a long flame. In certain instances this combustion chamber may be omitted, provided sufllcient com- "ture an additional layer of material is deposited discharge mechanism 37.

bustion space is present. so that the gases are completely burned and raised to a high temperature before they are applied to the surface of the material. The spent gases which have been drawn through the material and which may still retain considerable heat may be utilized in any convenient manner for the recovery of the waste heat therefrom.

At intervals along the roof and positioned transversely thereof, are a plurality of apertures through which the material is admitted in a manner to be pointed out. These apertures are preferably spaced uniformly and the first and last apertures are preferably located a substantial distance from the end walls of the heating chamber. The apertures are of such length that the material dropped through them is uniformly spread across the entire pallet.

A plurality of storage hoppers 36 are mounted above said apertures and are associated with a discharge mechanism, such as rotating drums-3'7, which receive material from said hoppers and apply the same through said apertures. A suitable control valve 38 may be associated with each hopperfor controlling the rate of discharge of materialtherefromjand a shield 39 may be associated with each of said discharge mechanisms to prevent escape of hot gases.

Cylinders 37 may be rotated by any convenient drive, as by gears 40, mounted on shaft 41, and driven by belt 42 which cooperates with one of said gears 16.

The preliminary feed hopper 45 is also supported on frame 10 and is located in front of heating chamber 25 in a position to apply the first layer of material to the pallets ast'hey are passed thereunder. This hopper may also be provided with an adjustable outlet, 'but does not require a feeding device since the conveyor elements passing beneath it carry out a layer of charge of the desired depth.

a In the operation of this form of the'invention which may, for exampla'be applied to the burning of clay, the clay or other material to be treated is supplied to each of the hoppers '36 and 45. As the pallets pass under hopper 45 they receive a thin bed of charge which may,-for example, be one-half inch'in thickness, this being regulated by adjustment of the discharge mechanism. This charge is carried into'the heating chamber and is heated by the hot gases-therein. Said gases are received from burners 31 and portsB'O, spread over the entire surface of the charge and are drawn "downwardly through the charge into wind box 20. The speed of travel of the pallets, the heat of the gases and the thickness of the layer 'are regulated so that the layer is completely burned and its heattreatment finished by the time it arrives beneath the first aperture 35.

When the layer passes beneath said first aperthereon from the cooperating hopper 36 and the This layer cools the lower layer by absorption of heat and it itself treated in a manner similar to the first layer as it is conveyed forward in the heating chamber.

The apparatus is so adjusted that the second layer is completely treated by the time the second aperture 35 is reached, whereupon a third layer will be deposited thereon and the treatment repeated. After the final layer has been deposited and heat treated, the pallets move out of the heating chamber and discharge their load as they'pass 'aroundthe curved. portion of the track.

It will be understood that the burners may be regulated to provide the proper temperature within the heating chamber, and the rate of travel of the conveyor likewise may be regulated as by control at the motor, and that various temperatures, rates of travel and thicknesses of layer will be suitable for various materials.

For example, when treating clay which has been crushed to pass half inch screen, it was found that with a temperature in the heating chamber of approximately 1800 F. a half inch layer of charge was burned in approximately three minutes, and the conveyor speed was correspondingly adjusted to give this time interval to each half inch layer. The finished product was discharged as a homogeneous cake with no indication of cleavage or separation between the layers, showing the unifor'mity andcompleteness of the heat treatment.

Referring to the form of the invention disclosed in Figs. 3 and 4: the apparatus is in generalsimilar to that described in connection with Figs. 1 and 2 and the corresponding parts have been given similar reference numerals. In this form of apparatus, however, an endlesspan conveyor is employed which is passed around sprocket wheels 51 and driven in any convenient manner. Saidpan conveyor is provided with an imperforate bottom and closely engages the bottom walls 28 of theheating chamber 25. In this form of the invention the hot gases are applied through suitable ports in roof 26 and are caused to impinge downwardly in the layer of material in pans 50. The gases, however, are not passed through the layer of material but are withdrawn through a stack 5:2 and discharged in any convenient manner. The hoppers are arranged as described in connectionwith Figs. '1 and 2' and successively apply layers of material to thepans as they pass thereunder. Each of said layers is heat treatedbeforethe next layer is added to the charge-and the treatment is otherwise similar to that above described. Withapparatus of this type, however, it may be preferable to employ somewhat thinner layers of charge than when the gases are drawn down through the layer as in Figs. 1 and 2. a

It will be noted that an efficient, economical apparatus is provided for heat treating the material in superimposed layers, which may be readily controlled by suitable regulation of the temperature, time, thickness of layer and speed of operation so that the process becomes substantially automatic and continuous and requires but little labor or attention. I

While certain novel features of the invent-ion have been disclosed and are pointed out-'in-the annexed claims, it will be understood that various omissions, substitutions and changes -may be made by those skilled in the art without departing from the spirit of the invention.

- material to said support, said feeding-means comprising hoppers and; discharge mechanism associated with each hopper and adapted to apply predetermined quantities of material to said support, and means for supplying a hot gaseousmedium over the entire surface of said material within said chamber.

'2. An apparatus for-heat treating materials comprising a heating chamber anda movable conveyor adapted to pass therethrough, said chamber having a plurality of transverse apertures spaced longitudinally thereof and extending across said conveyor, feeding means for feeding material through said apertures and causing said material to spread in uniform layers on said conveyor, and means for supplying a hot gaseous medium over the entire surface of said material within said chamber.

3. An apparatus for heat treating materials comprising a heating chamber and a movable conveyor adapted to pass therethrough, said chamber having a plurality of transverse apertures spaced longitudinally thereof and extending across said conveyor, means for continuously feeding material through each of said apertures and causing said material to form uniform layers on said conveyor, and means for supplying a hot gaseous medium over the entire surface of said material within said chamber.

4. An apparatus for heat treating materials comprising a heating chamber and a movable conveyor adapted to pass therethrough, said chamber having a plurality of transverse apertures spaced longitudinally thereof and means for continuously feeding material through each of said apertures and causing said material to form uniform layers on said conveyor, means for supplying hot gases over the entire surface of said material in said chamber and means for preventing escape of hot gases from said chamber through said apertures.

5. In a heat treating apparatus, a heating chamber, a movable support for passing a layer of material through said chamber, said chamber having a roof provided with a plurality of transverse openings through which successive layers of charge may be applied to said support, feeding means associated with each of said transverse openings, independent means for regulating the rate of feed from said feeding means through each of said apertures, and means for supplying a hot gaseous medium over the entire surface of said material within said chamber.

6. In a heat treating apparatus, a heatin chamber, a movable support for passing a layer of material through said chamber, said chamber having a roof provided with a plurality of transverse openings through which successive layers of charge may be applied to said support, feeding means associated with each of said transverse openings, discharge mechanism associated with each of said feeding means and adapted to remove material therefrom at a predetermined rate and to apply said material in a uniform manner through said openings, and means for supplying a hot gaseous medium over the entire surface of said material within said chamber.

'7. In a heat treating apparatus, a heating chamber, a movable support for passing a layer of material through said chamber, said chamber having a roof provided with a plurality of transverse openings through which successive layers of charge may be applied to said support, feeding means associated with each of said transverse openings, discharge mechanismassociated with each of said feeding means and adapted to remove material therefrom at a predetermined rate and to apply said material in a uniform manner through said openings, said discharge mechanism comprising a continuously rotating member adapted to pick up particles of charge from said feeding means and drop the same through said openings, and means for supplying a hot gaseous medium over the entire surface of said material within said chamber.

REED W. HYDE. 

